AK1543 Datasheet, PDF (14/35 Pages) Asahi Kasei Microsystems – 1300MHz Delta-Sigma FractionalSigma -N Frequency Synthesizer

[AK1543]
4. Lock Detect (LD) Signal
In the AK1543, “lock detect” output can be selected by D[11] = {LD} in <Address3>. When D[11] is set to “1" The phase
detector outputs provides a phase detection status as an analog level (comparison result). This is called analog lock
detect.
When D[11] is set to “0”, the lock detect signal is output according to the on-chip logic. This is called digital lock detect.
4.1 Analog Lock Detect
In analog lock detect, the phase detector output comes from the [LD] pin.
LDCKSEL=1
Reference clock
PFD clock
VCO divide clock
Phase detector output
LD output
Fig. 7 Analog Lock Detect Operations
MS1206-E-02
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2013/03